Jon Cave of the WordPress security team discovered that the
wp_validate_auth_cookie function in wp-includes/pluggable.php does
not properly determine the validity of authentication cookies,
allowing a remote attacker to obtain access via a forged cookie.

For the oldstable distribution (squeeze), these problems have been fixed
in version 3.6.1+dfsg-1~deb6u2.

For the stable distribution (wheezy), these problems have been fixed in
version 3.6.1+dfsg-1~deb7u2.

For the testing distribution (jessie), these problems have been fixed in
version 3.8.2+dfsg-1.

For the unstable distribution (sid), these problems have been fixed in
version 3.8.2+dfsg-1.